Síntesis de espirobrasinoesteroides análogos de la 6-desoxocastasterona
The synthesis of two new spirostanic analogs of the natural occurring brassinosteroid 6-desoxocastasterone (1) is described. The scheme consists in the formation and elimination of tigogenin mesylate followed by catalytic dihydroxylation of the resulting D2-steroid (3) and acetylation of the 2a, 3a-diol introduced.Treatment diacetate (5) with NaNO2/BF3.Et2O and chromatography in alumina led to a 23-keto (6) which on reduction produced the 23S alcohol (8) as major product. Saponification of the 2a, 3a-diacetoxy-23-keto compound (6) and the 2a,3a-diacetoxy-23-hydroxy compound (8) led to the spirobrasinosteroids (7) and (9).13C NMR and ¹H RMN characteristics derived from substitution at C23 are briefly discussed.
Main Authors: | , , , |
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Format: | Digital revista |
Language: | Spanish / Castilian |
Published: |
Sociedade Brasileira de Química
1997
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Online Access: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40421997000400004 |
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